Automated storage and retrieval system, a method of operating the system and a multi trolley vehicle

ABSTRACT

An automated storage and retrieval system that includes a rail system that includes a first set of parallel tracks arranged in a horizontal plane and extending in a first direction, and a second set of parallel tracks arranged in the horizontal plane and extending in a second direction that is orthogonal to the first direction. The first and second sets of tracks form a grid pattern in the horizontal plane including a plurality of adjacent grid cells, each grid cell includes a grid opening defined by a pair of neighboring tracks of the first set of tracks and a pair of neighboring tracks of the second set of tracks; and a plurality of stacks of storage containers arranged in storage columns located beneath the rail system, where each storage column is located vertically below a grid opening.

The present invention relates to an automated storage and retrievalsystem, a multi trolley vehicle for moving storage containers stacked instacks within the system and a method of operating such an automatedstorage and retrieval system.

BACKGROUND AND PRIOR ART

FIG. 1 discloses a framework structure 1 of a typical prior artautomated storage and retrieval system and FIGS. 2A-2C disclosedifferent container handling vehicles 9 of such a system.

The framework structure 1 comprises a plurality of upright members 2 anda plurality of horizontal members 3, which are supported by the uprightmembers 2. The members 2, 3 may typically be made of metal, e.g.extruded aluminium profiles.

The framework structure 1 defines a storage grid 4 comprising storagecolumns 5 arranged in rows, in which storage columns 5 store storagecontainers 6, also known as bins, are stacked one on top of another toform stacks 7. Each storage container 6 may typically hold a pluralityof product items (not shown), and the product items within a storagecontainer 6 may be identical, or may be of different product typesdepending on the application. The framework structure 1 guards againsthorizontal movement of the stacks 7 of storage containers 6, and guidesvertical movement of the containers 6, but does normally not otherwisesupport the storage containers 6 when stacked.

A rail system 8 is arranged in a grid pattern across the top of thestorage columns 5, on which rail system 8 a plurality of containerhandling vehicles 9 are operated to raise storage containers 6 from andlower storage containers 6 into the storage columns 5, and also totransport the storage containers 6 above the storage columns 5. The railsystem 8 comprises a first set of parallel rails 10 arranged to guidemovement of the container handling vehicles 9 in a first direction Xacross the top of the frame structure 1, and a second set of parallelrails 11 arranged perpendicular to the first set of rails 10 to guidemovement of the container handling vehicles 9 in a second direction Y,which is perpendicular to the first direction X. In this way, the railsystem 8 defines grid columns 12 above which the container handlingvehicles 9 can move laterally above the storage columns 5, i.e. in aplane which is parallel to the horizontal X-Y plane.

Each container handling vehicle 9 comprises a vehicle body 13 and firstand second sets of wheels 14, 15 which enable the lateral movement ofthe container handling vehicle 9, i.e. the movement in the X and Ydirections. In FIG. 2A two wheels in each of the sets 14, 15 arevisible, while in FIGS. 2B and 2C only two wheels in one of the set ofwheels 14 are visible. The first set of wheels 14 is arranged to engagewith two adjacent rails of the first set 10 of rails, and the second setof wheels 15 arranged to engage with two adjacent rails of the secondset 11 of rails. Each set of wheels 14, 15 can be lifted and lowered, sothat the first set of wheels 14 and/or the second set of wheels 15 canbe engaged with the respective set of rails 10, 11 at any one time.

Each container handling vehicle 9 also comprises a lifting device 16(see FIGS. 2B and 2C) for vertical transportation of storage containers6, e.g. raising a storage container 6 from and lowering a storagecontainer 6 into a storage column 5. The lifting device may be arrangedinside the body 13 (as in FIG. 2A) or outside the body 13 (as disclosedin FIGS. 2B and 2C). The lifting device 16 may comprise a lifting frame18 which is adapted to engage a storage container 6, which lifting frame18 can be lowered from the vehicle body 13 so that the position of thelifting frame with respect to the vehicle body 13 can be adjusted in athird direction Z, which is orthogonal the first direction X and thesecond direction Y.

Conventionally, and also for the purpose of this application, Z=1identifies the uppermost layer of the grid 4, i.e. the layer immediatelybelow the rail system 8, Z=2 the second layer below the rail system 8,Z=3 the third layer etc. In the embodiment disclosed in FIG. 1, Z=8identifies the lowermost, bottom layer of the grid 4. Consequently, asan example and using the Cartesian coordinate system X, Y, Z indicatedin FIG. 1, the storage container identified as 7′ in FIG. 1 can be saidto occupy grid location or cell X=10, Y=2, Z=3. The container handlingvehicles 9 can be said to travel in layer Z=0 and each grid column canbe identified by its X and Y coordinates.

Each container handling vehicle 9 comprises a storage compartment orspace for receiving and stowing a storage container 6 when transportingthe storage container 6 across the grid 4. The storage space maycomprise a cavity arranged centrally within the vehicle body 13 (FIG.2A), e.g. as is described in WO2014/090684A1, the contents of which areincorporated herein by reference. Alternatively, the storage compartmentor space can be arranged on the side of the body as disclosed in FIGS.2B and 2C, i.e. the container handling vehicles may have a cantileverconstruction, as is described in NO317366, the contents of which arealso incorporated herein by reference.

The container handling vehicles 9 may have a footprint 22 (see FIG. 4),i.e. an extension in the X and Y directions, which is generally equal tothe lateral or horizontal extension of a grid column 12, i.e. theextension of a grid column 12 in the X and Y directions, e.g. as isdescribed in WO2015/193278A1, the contents of which are incorporatedherein by reference. Alternatively, the container handling vehicles 9may have a footprint which is larger than the lateral extension of agrid column 12, e.g. as is disclosed in WO2014/090684A1.

The rail system 8 may be a single rail system, as is shown in FIG. 3.Alternatively, the rail system 8 may be a double rail system, as isshown in FIG. 4, thus allowing a container handling vehicle 9 having afootprint 22 generally corresponding to the lateral extension of a gridcolumn 12 to travel along a row of grid columns even if anothercontainer handling vehicle 9 is positioned above a grid columnneighbouring that row.

In a storage grid, a majority of the grid columns 12 are storage columns5, i.e. grid columns where storage containers are stored in stacks.However, a grid normally has at least one grid column which is used notfor storing storage containers, but which comprises a location where thecontainer handling vehicles can drop off and/or pick up storagecontainers so that they can be transported to an access station wherethe storage containers can be accessed from outside of the grid ortransferred out of or into the grid. Within the art, such a location isnormally referred to as a “port” and the grid column in which the portis located may be referred to as a port column.

The grid 4 in FIG. 1 comprises two port columns 19 and 20. The firstport column 19 may for example be a dedicated drop-off port column wherethe container handling vehicles 9 can drop off storage containers to betransported to an access or a transfer station (not shown), and thesecond port 20 column may be a dedicated pick-up port column where thecontainer handling vehicles 9 can pick up storage containers that havebeen transported to the grid 4 from an access or a transfer station.

The access station may typically be a picking or a stocking stationwhere product items are removed from or positioned into the storagecontainers. In a picking or a stocking station, the storage containersare normally never removed from the automated storage and retrievalsystem, but are returned back into the grid once accessed. A port canalso be used for transferring storage containers out of or into thegrid, e.g. for transferring storage containers to another storagefacility (e.g. to another grid or to another automated storage andretrieval system), to a transport vehicle (e.g. a train or a lorry), orto a production facility.

A conveyor system comprising conveyors is normally employed to transportthe storage containers between the ports and the access station.

If the port and the access station are located at different levels, theconveyor system may comprise a lift device for transporting the storagecontainers vertically between the port and the access station.

The conveyor system may be arranged to transfer storage containersbetween different grids, e.g. as is described in WO2014/075937A1, thecontents of which are incorporated herein by reference.

WO2016/198467A1, the contents of which are incorporated herein byreference, disclose an example of a prior art access system havingconveyor belts (FIGS. 5a and 5b in WO2016/198467A1) and a frame mountedtrack (FIGS. 6a and 6b in WO2016/198467A1) for transporting storagecontainers between ports and work stations where operators can accessthe storage containers.

When a storage container 6 stored in the grid 4 disclosed in FIG. 1 isto be accessed, one of the container handling vehicles 9 is instructedto retrieve the target storage container from its position in the grid 4and transport it to the drop-off port 19. This operation involves movingthe container handling vehicle 9 to a grid location above the storagecolumn in which the target storage container is positioned, retrievingthe storage container from the storage column using the containerhandling vehicle's lifting device (not shown), and transporting thestorage container to the drop-off port 19. If the target storagecontainer 6 is located deep within a stack 7, i.e. with one or aplurality of other storage containers positioned above the targetstorage container, the operation also involves temporarily moving theabove-positioned storage containers prior to lifting the target storagecontainer from the storage column. This step, which is sometimesreferred to as “digging” within the art, may be performed with the samecontainer handling vehicle 9 that is subsequently used for transportingthe target storage container to the drop-off port 19, or with one or aplurality of other cooperating container handling vehicles 9.Alternatively, or in addition, the automated storage and retrievalsystem may have container handling vehicles 9 specifically dedicated tothe task of temporarily removing storage containers 6 from a storagecolumn. Once the target storage container has been removed from thestorage column, the temporarily removed storage containers 6 can berepositioned into the original storage column. However, the removedstorage containers 6 may alternatively be relocated to other storagecolumns.

When a storage container 6 is to be stored in the grid 4, one of thecontainer handling vehicles 9 is instructed to pick up the storagecontainer from the pick-up port 20 and transport it to a grid locationabove the storage column where it is to be stored. After any storagecontainers 6 positioned at or above the target position within thestorage column stack have been removed, the container handling vehicle 9positions the storage container 6 at the desired position. The removedstorage containers may then be lowered back into the storage column, orrelocated to other storage columns.

For monitoring and controlling the automated storage and retrievalsystem, e.g. monitoring and controlling the location of respectivestorage containers within the grid 4, the content of each storagecontainer 6, and the movement of the container handling vehicles 9 sothat a desired storage container can be delivered to the desiredlocation at the desired time without the container handling vehicles 9colliding with each other, the automated storage and retrieval systemcomprises a control system, which typically is computerised andcomprises a database for keeping track of the storage containers.

With known automated storage and retrieval systems, the area surroundingthe ports may become congested with container handling vehiclesinstructed to drop off or pick up storage containers. This may seriouslyimpede the operation of the automated storage and retrieval system. Insmall systems this situation may possibly be alleviated by adding portsto the grid, as this will allow the container handling vehicles to bedistributed among a larger number of ports in order to avoid congestion.However, if ports are added, the conveyor system infrastructure mustnormally be increased. This requires space, which may not necessarily beavailable. Also, adding conveyor system infrastructure is costly.

Furthermore, the current trend within the automated storage andretrieval system industry is that there is an increasing demand forlarger storage grids. Since the number of storage containers stored in agrid generally scales as the volume of the grid, but the space availablefor ports generally scales as the surface of the grid, increasing thenumber of ports will not satisfactory alleviate the congestion problemwhen the grid size increases.

In view of the above, one or more embodiments of the invention mayprovide an automated storage and retrieval system, and a method foroperating such a system, that reduce congestion of container handlingvehicles at the ports.

One or more embodiments of the invention may increase the capacity interms of moving more storage containers in less time than in the priorart.

SUMMARY OF THE INVENTION

The invention is set forth in the independent claims and the dependentclaims describe alternatives of the invention.

The invention relates to an automated storage and retrieval systemcomprising:

-   -   a rail system comprising a first set of parallel tracks arranged        in a horizontal plane and extending in a first direction, and a        second set of parallel tracks arranged in the horizontal plane        and extending in a second direction which is orthogonal to the        first direction, which first and second sets of tracks form a        grid pattern in the horizontal plane comprising a plurality of        adjacent grid cells, each comprising a grid opening defined by a        pair of neighboring tracks of the first set of tracks and a pair        of neighboring tracks of the second set of tracks; and    -   a plurality of stacks of storage containers arranged in storage        columns located beneath the rail system, wherein each storage        column is located vertically below a grid opening;

wherein the system further comprises:

a multi trolley vehicle for transporting storage containers between thestorage columns and at least one deployment area, which deployment areaprovides direct access to an area outside the grid pattern, the multitrolley vehicle comprising:

a trolley assembly comprising a plurality of trolleys coupled to eachother along at least one of the first direction and second direction,where

each trolley provides at least one container volume for storing at leastone of the storage containers, and where

each trolley comprises moving devices allowing movement of the trolleyassembly in at least one of the first direction and/or the seconddirection, and where

at least one of the trolleys comprises non-motorized moving devices, and

a first drive vehicle coupled to the trolley assembly, the first drivevehicle comprising motorized moving devices allowing self-propelledmovement of the first drive vehicle and thereby the multi trolleyvehicle in at least one of the first and second directions correspondingto the at least one of the first and second directions of the trolleyassembly, such that the multi trolley vehicle is horizontally movable.

Thus, according to the invention, a drive vehicle connected to a trolleyassembly, the setup which is also referred to as multi trolley vehicle,is capable of transporting one or a group of storage containers betweenthe storage columns and the at least one deployment area, whichdeployment area provides direct access to an area outside the gridpattern. Furthermore, the rail system is preferably only the top layerof the automated storage and retrieval system, the storage columns aredefined volumes below the rail system.

The system is provided with at least one drive vehicle, i.e. the firstdrive vehicle, on one end of the trolley assembly or partway or midwaywithin the trolley assembly, thereby defining a multi trolley vehicle.The at least one drive vehicle can thus be seen as locomotive, towingvehicle, hauling vehicle, traction engine, tractive machine, tractiveunit, tractor, i.e. any vehicle capable of being connected to thetrolley assembly. Various terms are used in the following description ofthe system defined by at least one drive vehicle connected to a trolleyassembly, including multi trolley vehicle. If the system comprises morethan one drive vehicle, e.g. also a second drive vehicle, thecombination of drive vehicles and trolley assembly is still referred toas a multi trolley vehicle. The drive vehicle(s) may either push or pullthe trolley assembly, and can be arranged in front of, and or behind,and or partway within, said trolley assembly. Alternatively, the drivevehicle(s) may also pull or drag the trolley assembly sideways. In thislatter aspect, the drive vehicles and the trolleys are preferablyconfigured with moving devices directed in both the X direction and Ydirection. The deployment area can in one aspect be a port, in anotheraspect be a factory area, in yet another aspect be a productionfacility, in yet another aspect another rail or grid system with orwithout a dedicated storage system. In one aspect, if the deploymentarea is a port or port area which has access from outside the gridpattern (rail system), the port or port area can be arranged within oroutside of the grid pattern, either extending along an end row orextending into or out from the the grid pattern. Furthermore, the atleast one drive vehicle and trolley assembly can move on the rail systemor in a plane horizontally above or below the rail system (for exampleon a double rail). If driving in a plane horizontally below the railsystem, the at least one drive vehicle and trolley assembly can functionas a conveyor belt for the storage containers. In another aspect, if thedeployment area is a factory area, a production facility or another gridor rail system, direct access to an any of the latter areas which areoutside the grid pattern is achieved. The multi trolley vehicle can moveon the rail system, dedicated transport rails between the rail systemand deployment area, on a double rail above or below the rail system orcombinations thereof. The multi trolley vehicle can further transportstorage containers from the deployment area to a storage position, i.e.a column in the grid. Thus, in an aspect where the deployment area isfar away from the grid or rail system, the multi trolley vehicleprovides for fast transfer of storage containers between the rail systemand deployment area, and the deployment area and the grid or railsystem.

If the deployment area is a factory area, it can be a service area whereservice may be conducted on the trolleys and or any of the drivevehicles manually or by machines.

The number of trolleys in one trolley assembly can easily be varied, andcan be adapted based on the number of columns in the deployment area andor in a transfer zone, i.e. any number of trolley(s) can be added orsubtracted from the trolley assembly thereby changing the number oftrolleys making up the trolley assembly. One trolley can provide forlifting of more than one storage container and the trolley may occupymore than one row in the width and or length direction of the multitrolley vehicle. In the latter case, one trolley may be configured withmore than one lifting devices, for example the number of lifting devicesin one trolley corresponds to the number of cells occupied by the onetrolley. Furthermore, the area occupied by one trolley may be smallerthan, or substantially equal to, the size of a single cell. However, theoccupied area of one trolley may also be larger than a single cell.

In an aspect, the automated storage and retrieval system furthercomprises a plurality of container handling vehicles which are operatedon the rail system for retrieving storage containers from and storingstorage containers in the storage columns, and for transporting thestorage containers horizontally across the rail system. Furthermore, therail system may comprise at least one transfer zone with underlyingtransfer columns for temporarily storing storage containers when intransit between the plurality of storage columns and the at least onedeployment area, wherein the container handling vehicles are arranged totransport the storage containers between the storage columns and the atleast one transfer zone.

Thus, the container handling vehicles are utilised to transport thestorage containers between the storage columns and the transfer columnsin the transfer zone.

The transfer zone is defined as a 2D area (in the Z and Y directions) ontop of the rail system, i.e. the tracks, and the storage containers canbe stored below the rail system or on top of the rail system from Z=0 toZ=X, where X is number of the lowermost storage position in the grid.

As compared to providing more ports to alleviate congestion, it is easyto increase the number of transfer columns in the transfer zone in therail system. Furthermore, the transfer columns in the transfer zone(s)can be located inside the rail system, e.g. at a distance within thecircumference of the rail system, thus allowing the container handlingvehicles access to the transfer columns from the X and Y directions. Aport, on the other hand, is normally located at the circumference of therail system and, therefore, is normally only accessible from onedirection. The transfer columns are preferably standard columns, and thelocation of the transfer zones with transfer columns in the rail systemcan be computer operated, thereby the position of the transfer zone andthereby the transfer columns can be programmed to be at the mostconvenient location, and can be continuously changed. The transfercolumns can be a row of 1, 2, 3, 4, 5, 6, . . . , 10, . . . , 15 singlecells in the rail system or more. A single cell is the area defined bytwo pairs of opposing bars in the X and Y directions.

One transfer zone comprises a plurality of neighboring individualtransfer columns. The transfer columns can further be along more thanone row, e.g. 2, 3 or more parallel rows, either neighboring rows ornot. The transfer zones, i.e. the transfer columns, can thus preferablybe moved in the same direction as the direction of travel of the multitrolley vehicle(s). The location of the transfer zone(s), i.e. thetransfer columns, is thus preferably always temporarily. This renderspossible freeing up area on the rail system dependent on the operationof the container handling vehicles and or other vehicles moving on therail system. For example, if a target bin is below, i.e. for example atZ=8, and a temporarily transfer column is at Z=6, the transfer zone, andthereby the transfer column, can easily be relocated such that acontainer handling device can access the container at Z=8.

Furthermore, this temporarily location of the transfer zones, allows forflexibility and provides maximum storage capacity in the grid system.

It may be advantageous if the transfer columns form a transfer zone andthe at least one port form a port zone, wherein the transfer zone isadjacent the port zone. Alternatively, the transfer zone may be arrangedat a distance from the port zone.

In an aspect, all moving devices in each trolley are non-motorized. Inthis aspect, the at least one drive vehicle is a master vehicle and allof the trolleys in the trolley assembly are slave vehicles.

In another aspect, one or more of the trolleys comprises motorizedmoving devices. To provide the trolleys with motorized moving devicescan be advantageous in situations where a plurality of trolleys are usedbecause the drag/push capacity of the drive vehicle(s) can be limited,i.e. insufficient to drag/push a plurality of trolleys.

In an aspect, the moving devices comprise wheels.

In another aspect, the moving devices comprise belts.

According to an aspect, the multi trolley vehicle is arranged totransport the storage containers between the at least one transfer zoneand the at least one deployment area on the rail system, or in a planelocated above or below the rail system. The transporting of thecontainers can be along at least a double rail, e.g. two parallel rails.By transporting the storage containers between the transfer columns inthe transfer zone and the deployment area in a plane, for example on adouble rail, which is located above or below the container handlingvehicles, i.e. above or below the plane where the container handlingvehicles travel across the rail system, any interference on the transferof the storage containers between the transfer columns and thedeployment area may have on the movement of the container handlingvehicles will be minimized. The double rail may be suspended from theceiling, be fastened to the walls, be supported on dedicated supportlegs, be mounted on the grid structure etc.

Each drive vehicle can occupy a single cell or more than one cell.Similarly, each trolley can occupy a single cell or more than one cell.Thus, the multi trolley vehicle may occupy one row, or may extend overmore than one row, e.g. 1, 2, 3, 4, 5 . . . 10 rows to increase thetransport capacity. This means that according to one aspect of theinvention the size of the at least one trolley may occupy a single cellor, alternatively in another aspect of the invention, one trolley mayoccupy more than one cell both in the direction of travel and/or in thedirection perpendicular to the direction of travel (i.e. in the X and orY directions on the rail system). According to this latter aspect, eachtrolley can be provided with a plurality of lifting devices, e.g.elevators, for lifting and lowering storage containers between a columnin the grid and a compartment for the storage containers in the trolley,which number of elevators corresponds to the number of cells occupied bythe trolley. Furthermore, the drive vehicle(s) can occupy less rows thanthe connected trolleys, e.g. the drive vehicle(s) can occupy one row,whereas the trolley or trolley assembly can extend over 2 or more rows.

In an aspect, the system may comprise a second drive vehicle withmotorized driving devices allowing self-propelled movement of the seconddrive vehicle in at least one of the first direction and/or the seconddirection, which second drive vehicle is connectable to a second end ofthe trolley assembly.

In an aspect, the first drive vehicle is arranged to transport thetrolley assembly in a first direction, and the second drive vehicle isarranged to transport the trolley assembly in a second direction, whichsecond direction is opposite the first direction.

In an aspect, the motorized moving devices of the first drive vehicleconnected to the first end of the trolley assembly are configured toallow self-propelled, one-way movement along at least one of the firstdirection and/or the second direction and the motorized moving devicesof the second drive vehicle connected to the second end of the trolleyassembly are configured to allow self-propelled, one-way movement alongan opposite direction of the at least one first direction and the seconddirection.

The connections between each trolley in the trolley assembly and any ofthe first drive vehicle and second drive vehicle may in an aspect allowa certain degree of movement between two adjacent trolleys and or thefirst or second drive vehicle in at least one direction, i.e. theconnection is configured to allow movements along the direction ofcoupling corresponding to at least 1% of the length of the respectivecoupling, thereby allowing the multi-trolley vehicle to follow curves ina track or go up a slope. Such connection may be mechanical connections,such as a pivot connection allowing some vertical and horizontalmovement between adjacent trolleys or drive vehicles, a hook system,magnetic connection etc. A mechanical connection may e.g. be a singlebracket, or two brackets connectable to each other, wherein thebracket(s) are fixed with fastening elements to adjacent trolleys ordrive vehicles and provide some flexibility in the vertical direction,i.e. in the Z direction (if the driving direction is in the X or Ydirection). As such, possible challenges related to irregularities onthe rail system surface, such as particles, is greatly reduced.

The fastening elements may be screws or bolts or any other suitablefastening elements, or combinations thereof. In order to provideflexibility in the capacity and size of the multi trolley vehicle, theconnection between the trolleys and any drive vehicles can bedisconnectable, allowing easy addition of or, removal of, trolleys fromthe multi trolley vehicle.

In an aspect, a drive system in the at least first drive vehiclecomprises a hub motor arranged within each of the moving devices.Alternatively, the drive system in the at least first, second or anyadditional drive vehicle may comprise an electric drive system, a directdrive system, a master wheel driving the driving elements as describedin WO 2015/193278 hereby incorporated by reference, a motor rotor drivenby a stator, an electric system etc. An example of such motor rotordriven by an internal stator is shown in EP 3 050 824 A1, which documentis incorporated herein by reference. If using wheels or belts as themoving devices, the complete motor can be arranged inside the externalboundaries defined by the wheel (e.g. wheel rim etc.).

Furthermore, if one or more of the trolleys in the trolley assemblycomprises motorized moving devices, the drive system for the motorizedmoving devices may comprise similar solutions as described above inrelation to the at least first, second or any additional drive vehicle.

In an aspect, each trolley may comprise an open bottom end and a closedtop end, and wherein a lifting device, such as an elevator, can beconnected to the top end for lifting and lowering storage containersbetween a storage column and the compartment in the trolley.

The system may further comprise a port access vehicle, which port accessvehicle comprises a plurality of vehicle sections which are connectedone after the other in a train-like configuration, which vehiclesections each being configured to carry at least one storage container,and a plurality of container lifting and holding devices enablingsimultaneous transport of a plurality of storage containers between therail system and the deployment area, and wherein the port access vehicleis arranged to transport the storage containers between the rail systemand the at least one deployment area in a plane located above the railsystem. The train-like configuration allows for the port access vehicleto be easily adapted to changing conditions in the grid or rail system.The port access vehicle may be operated on the rail system, e.g. bearranged to travel along the rail system of the grid. Alternatively, theport access vehicle may be operated on a monorail or double railarranged in a parallel horizontal plane above the rail system.

In an aspect, each trolley may comprise a closed bottom end and an opentop end for receiving storage containers from above. This is renderedpossible by for example allowing the trolley assembly to cooperate withone or more stationary lifting arrangements, using e.g. a port accessvehicle, or using another multi trolley vehicle operating in the same Xand Y rows but in different Z locations, i.e. arranged directly abovethe trolleys. It may be advantageous if the port access vehiclecomprises a first lifting and transfer device arranged to carry astorage container from one of the transfer columns to the trolleys.

In order to increase the capacity of the port access vehicle, it may beadvantageous if the port access vehicle comprises a plurality ofcontainer lifting and holding devices enabling simultaneous transport ofa plurality of storage containers between the transfer columns in thetransfer zone and the at least one port.

The invention further relates to a multi trolley vehicle operable on anautomated storage and retrieval system as defined above for movingstorage containers between stacks within a grid pattern formed byhorizontal first and second set of parallel tracks and a deploymentarea, which deployment area provides direct access to an area outsidethe grid pattern formed by first and second sets of parallel tracks,wherein the multi trolley vehicle is configured to move on the railsystem above the storage columns and comprises a trolley assemblycomprising a plurality of trolleys coupled to each other along at leastone of a first direction and second direction, where

-   -   each trolley provides at least one container volume for storing        at least one of the storage containers, and where    -   each trolley comprises moving devices allowing movement of the        trolley assembly in at least one of the first direction and/or        the second direction, and    -   at least one of the trolleys comprises non-motorized moving        devices, and    -   a first drive vehicle coupled to the trolley assembly, the first        drive vehicle comprising motorized moving devices allowing        self-propelled movement of the first drive vehicle and thereby        the multi trolley vehicle in at least one of the first and        second directions corresponding to the at least one of the first        and second directions of the trolley assembly, such that the        multi-trolley vehicle is horizontally movable. Preferably, each        trolley comprises a lifting device for lifting a storage        container.

It is further described a multi trolley vehicle comprising a trolleyassembly comprising a plurality of trolleys coupled to each other alongat least one of a first direction and second direction, where

each trolley comprise a closed bottom end and an open top end forreceiving a storage container from above, and

where each trolley displays at least one container volume for storing atleast one of the storage containers above the closed bottom end, and

where each trolley comprises moving devices allowing movement of thetrolley assembly in at least one of the first direction and/or thesecond direction, and at least one of the trolleys comprisesnon-motorized moving devices, and

a first drive vehicle coupled to the trolley assembly, the first drivevehicle comprising motorized moving devices allowing self-propelledmovement of the first drive vehicle and thereby the multi trolleyvehicle in at least one of the first and second directions correspondingto the at least one of the first and second directions of the trolleyassembly, such that the multi-trolley vehicle is horizontally movable.

In this latter multi trolley vehicle each trolley comprises a closedbottom end and an open top end for receiving storage containers fromabove. This is rendered possible by for example allowing the trolleyassembly to cooperate with one or more stationary lifting arrangements,using e.g. a port access vehicle, container handling vehicles or usinganother multi trolley vehicle operating in the same X and Y rows but indifferent Z locations, i.e. arranged directly above the trolleys. It maybe advantageous if the port access vehicle comprises a first lifting andtransfer device arranged to carry a storage container from one of thetransfer columns or in port zones lifting or lowering storage containersonto and or off from the trolleys. Thus, it is clear that this multitrolley vehicle can function as a conveyor belt, for example in the portzone, rendering the use of traditional conveyor belts in this areasuperfluous.

In an aspect, the container volume of the trolley comprises acompartment for fully containing storage containers within a body of thetrolley or on the side of the body (cantilever construction).

In an aspect, the multi trolley vehicle further comprises a second drivevehicle with motorized driving devices allowing self-propelled movementof the second drive vehicle in at least one of the first direction andthe second direction, which second drive vehicle is connectable to asecond end of the trolley assembly.

The invention further relates to method of operating an automatedstorage and retrieval system, the automated storage and retrieval systemcomprising:

a rail system comprising a first set of parallel tracks arranged in ahorizontal plane and extending in a first direction, and a second set ofparallel tracks arranged in the horizontal plane and extending in asecond direction which is orthogonal to the first direction, which firstand second sets of tracks form a grid pattern in the horizontal planecomprising a plurality of adjacent grid cells, each comprising a gridopening defined by a pair of neighboring tracks of the first set oftracks and a pair of neighboring tracks of the second set of tracks; anda plurality of stacks of storage containers arranged in storage columnslocated beneath the rail system, wherein each storage column is locatedvertically below a grid opening; which method comprises:

-   -   connecting a trolley assembly comprising a plurality of trolleys        to at least a first drive vehicle comprising motorized moving        devices to form a multi trolley vehicle, and utilizing said        multi trolley vehicle to transport the storage containers        between the storage columns and at least one deployment area,        which deployment area provides direct access to an area outside        the grid pattern formed by the first and second sets of tracks.

In an aspect, the method further comprises:

-   -   operating a control system to define at least one transfer zone        comprising a plurality of transfer columns for temporarily        storing storage containers when in transit between the storage        columns and the at least one deployment area;    -   utilizing container handling vehicles which are operated on the        rail system for retrieving storage containers from and storing        storage containers in the transfer columns, and for transporting        the storage containers horizontally across the rail system; and        wherein the step of transporting the storage containers between        the transfer columns and the at least one deployment area        comprises utilizing a port access vehicle cooperating with the        multi trolley vehicle, which port access vehicle comprises a        plurality of vehicle sections which are connected one after the        other in a train-like configuration in a horizontal plane which        is located above the horizontal plane of the rail system where        the container handling vehicles and the multi trolley vehicle        operate, which vehicle sections each being configured to carry        at least one storage container, and wherein    -   the trolleys comprise a closed bottom end are adapted to receive        storage containers from above, and wherein the method comprises        operating the port access vehicle to lower storage containers on        to the trolleys, and subsequently operating the multi-trolley        vehicle to transport the storage containers to the deployment        area, wherein a second port access vehicle is arranged in the        deployment area for lifting the storage containers from the        trolleys.

In the following description, numerous specific details are introducedby way of example only to provide a thorough understanding ofembodiments of the claimed system and method. One skilled in therelevant art, however, will recognize that these embodiments can bepracticed without one or more of the specific details, or with othercomponents, systems, etc. In other instances, well-known structures oroperations are not shown, or are not described in detail, to avoidobscuring aspects of the disclosed embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Following drawings are appended to facilitate the understanding of theinvention;

FIG. 1 is a perspective view of a grid with a rail system of a prior artautomated storage and retrieval system;

FIG. 2A is a perspective view of a first prior art container handlingvehicle;

FIG. 2B is a perspective view of a second prior art container handlingvehicle;

FIG. 2C is a side view of the second prior art container handlingvehicle in FIG. 2B, showing a lifting device, i.e. elevator, for liftingand or lowering storage containers;

FIG. 3 is a top view of a prior art single rail grid;

FIG. 4 is a top view of a prior art double rail grid;

FIG. 5A is a perspective view of an exemplary system according to theinvention, showing a first drive vehicle connected to a first end of atrolley assembly comprising six trolleys and a second drive vehicleconnected to an opposite second end of the trolley assembly;

FIG. 5B is a side view of the system of FIG. 5A;

FIG. 5C is an end view of the system of FIGS. 5A and 5B;

FIG. 5D is a top view of FIGS. 5A-5C;

FIG. 6A is a perspective view of an embodiment of the invention where amulti trolley vehicle comprising a first and second drive vehicleconnected at each end to a trolley assembly moves on a double rail abovethe rail system where container handling vehicles operates;

FIG. 6B is a side view of the embodiment in FIG. 6A;

FIG. 7A is an example of an embodiment of the invention where storagecontainers are lowered down onto the trolleys in the trolley assembly bycontainer handling vehicles;

FIG. 7B is an example of an embodiment of the invention where storagecontainers are lowered down onto the trolleys in the trolley assembly bycontainer handling vehicles or an upper multi trolley vehicle operatingin a horizontal plane above the trolley assembly in a lower multitrolley vehicle;

FIG. 8A is a perspective view of a first and second drive vehicleconnected at opposite ends of a trolley assembly driving on a doublerail consisting of three parallel rows a level above the rail system;

FIG. 8B is an end view of the drive vehicle, double rail and rail systemof FIG. 8A;

FIGS. 9A-9B are different views of cooperation between a port accessvehicle and a drive vehicle with a trolley assembly;

FIG. 10 is a perspective view of FIGS. 9A and 9B;

FIG. 11 is a top view of grid of an automated storage and retrievalsystem according to one embodiment of the invention;

FIG. 12 is a perspective view of a port access vehicle which can formpart of the system in accordance with the invention;

FIGS. 13 and 14 are orthogonal side views of a vehicle section of theport access vehicle in FIG. 12;

FIG. 15 is a top view of a rail system on top of a grid showingdifferent transfer zone configurations;

FIGS. 16A, 16B and 16C show examples of different deployment areas,where FIG. 16A shows a deployment area being another grid or railsystem, FIG. 16B shows the deployment areas being otherstorage/warehouse systems, and where FIG. 16C shows the deployment areabeing a factory area or production facility and where the drive vehicleand trolley assembly is configured to move on a double rail formed as aloop between the grid or rail system and the factory area or productionfacility;

In the drawings, like reference numerals have been used to indicate likeparts, elements or features unless otherwise explicitly stated orimplicitly understood from the context.

DETAILED DESCRIPTION OF THE INVENTION

In the following, embodiments of the invention will be discussed in moredetail with reference to the appended drawings. It should be understood,however, that the drawings are not intended to limit the invention tothe subject-matter depicted in the drawings. Furthermore, even if someof the features are described in relation to the system only, it isapparent that they are valid for the method and the multi trolleyvehicle as well, and vice versa, i.e. any features described in relationto the method only are also valid for the system and multi trolleyvehicle.

FIG. 3 is a top view of a cell of a grid 4 with a rail system 8 of theautomated storage and retrieval system. The grid 4 comprises a frameworkstructure 1 comprising a plurality of upright members 2 (see FIG. 1) anda plurality of horizontal members 3 which are supported by the uprightmembers. As is known in the art, the upright and horizontal members maytypically be made of metal, e.g. extruded aluminium profiles. The uppersurface of the grid 4 has a rail system 8. The rail system 8 comprises afirst set of parallel tracks 10 arranged in a horizontal plane P andextending in a first direction X, and a second set of parallel tracks 11arranged in the horizontal plane P and extending in a second direction Ywhich is orthogonal to the first direction X. The first and second setsof tracks 10, 11 form a grid pattern in the horizontal plane Pcomprising a plurality of adjacent grid cells, each comprising a gridopening 12 defined by a pair of neighboring tracks 10 a, 10 b of thefirst set of tracks 10 and a pair of neighboring tracks 11 a, 11 b ofthe second set of tracks 11. The example grid openings 12 in FIGS. 3 and4 are part of the overall rail system 8 (see FIG. 1)

A general description of an automated storage and retrieval systemaccording to the invention will now be discussed in more detail withreference to FIG. 11. The horizontal members 3 comprise a rail system 8arranged in a grid pattern across the top of the storage columns, onwhich rail system 8 a plurality of container handling vehicles 9 areoperated. The rail system 8 comprises a first set of parallel rails 10arranged to guide movement of the container handling vehicles 9 in afirst direction X across the top of the frame structure 1, and a secondset of parallel rails 11 arranged perpendicular to the first set 10 toguide movement of the container handling vehicles 9 in a seconddirection Y that is perpendicular to the first direction X. In this way,the rail system 8 defines grid columns 12 in the horizontal X-Y plane,above which grid columns 12 the container handling vehicles 9 can movehorizontally in the X and Y directions. Consequently, the horizontalarea of a grid column 12, i.e. along the X and Y directions, may bedefined by the distance between adjacent rails 10 and 11, respectively(details in FIG. 4). Consequently, the rail system 8 allows thecontainer handling vehicles 9 to move horizontally in the X-Y planebetween different grid locations, where each grid location is associatedwith a grid column 12.

The container handling vehicles 9 may be of any type known in the art,e.g. any one of the automated container handling vehicles 9 discussed inrelation to FIGS. 1 and 2A, 2B, 2C. It may be advantageous if eachcontainer handling vehicle 9 comprises a centrally located storage spacefor receiving and stowing a storage container 6 when transporting thestorage container horizontally across the rail system 8, and afootprint, i.e. an extent in the X and Y directions, which is generallyequal the horizontal extent of a grid column 12. This will allow acontainer handling vehicle 9 to transport a storage container above arow of grid columns even if another container handling vehicle 9occupies a location above a grid column neighboring the grid column rowalong which the first container handling vehicle is traveling.Alternatively, container handling vehicles of cantilever constructioncan also be used.

In the disclosed embodiment of FIG. 11, the grid 4 or rail system 8comprises a storage zone 25, two port zones 26 and two transfer orbuffer zones 35. Each port zone 26, which is, for example, three gridcells wide in the X direction and seven grid cells long in the Ydirection, comprises ports 28, 29 where storage containers can betransferred out of or into the grid 4. Each transfer zone 35, thefunction of which is discussed in more detail below, is three grid cellswide (rows denoted 38, 39, 40 in the X direction) and 43 grid cells long(in the Y direction) in the example shown. The storage zone 25, whichmakes up the rest of the rail system 8, comprises storage columns 5 inwhich storage containers or bins 6 can be stacked one on top of anotherto form stacks 7.

FIGS. 5A-5D show example of a system according to the invention. FIG. 5Ashows a first drive vehicle 70 connected to a first end of a trolleyassembly 72 comprising six trolleys 72′ connected to each other and asecond drive vehicle 71 connected to an opposite second end of thetrolley assembly 72. This setup is generally denoted as a ‘multi trolleyvehicle’ with reference number 100. However, the multi trolley vehicle100 in the simplest form, may have only one drive vehicle and a trolleyassembly 72 comprising one trolley 72′. FIG. 5B is a side view of thesystem of FIG. 5A. FIG. 5C is an end view of the system of FIGS. 5A and5B, while FIG. 5D is a top view of FIGS. 5A-5C.

It is disclosed an automated storage and retrieval system comprising athree-dimensional grid 4 comprising a plurality of storage columns 5 inwhich storage containers are stored one on top of another in verticalstacks (see FIG. 1 for detailed view of storage containers 6 and stacks7). Each trolley 72′ comprises moving devices, such as a first set ofwheels 14, 15, and are arranged to transport the storage containers 6.The first and second drive vehicles 70, 71 comprise motorized movingdevices, in FIG. 5A shown as motorized first set of wheels 14, 15.Preferably, the first drive vehicle 70 is arranged to transport thetrolley assembly 72 in a first direction, and the second drive vehicle71 is arranged to transport the trolley assembly 72 in a seconddirection, which second direction is opposite the first direction.However, in cases with only one drive vehicle 70, 71, the one drivevehicle can drive in both directions (i.e. both pushing and pulling thetrolley assembly 72). In yet another aspect the drive vehicle(s) 70, 71and trolley assembly 72 can drive in both X and Y directions. Accordingto this latter aspect, the drive vehicles and trolleys can be providedwith two set of wheels, one set for each X and Y directions where theset of wheels not used can be temporarily lifted up from contact withthe rails, as is known in the art.

The first and second drive vehicles 70, 71 are connectable to a firstend of the trolley assembly 72 via connections 17. Alternatively, thedrive vehicle(s) 70, 71 can be connected partway or midway within thetrolley assembly (72). The connection 17 between each trolley 72′ in thetrolley assembly 72 and any of the first drive vehicle 70 and seconddrive vehicle 71 allows a certain degree of movement between twoadjacent trolleys 72′ and or the first or second drive vehicle 70, 71,in at least one direction. In the disclosed embodiment it is shown asingle bracket which is connected to respective adjacent trolleys 72′and/or drive vehicle 70, 71. The multi trolley vehicle 100 is arrangedto transport the storage containers 6 between a storage column 5(exemplified as a transfer column 36 in a transfer zone 35 and at leastone deployment area (see FIGS. 16A-16C for illustrations of differentdeployment areas).

The transfer columns 36, 37 in the transfer zones 35 are preferablystandard columns 5, and the location of the transfer columns 36, 37 inthe grid or on the rail system 8 can be computer operated, thereby theposition of the transfer zone 35, and thus the transfer columns 36, 37,can be programmed to be at the most convenient location, and can becontinuously changed. The transfer columns 36, 37 can further be alongmore than one row, e.g. 2, 3 or more parallel rows, either neighboringrows or not. The transfer zone 35, and thus the transfer columns 36, 37,can thus preferably be moved along the same row as the direction oftravel of the at least first vehicle 70, 71 and trolley assembly 72,i.e. the multi trolley vehicle 100. The location of the transfer zonesand transfer columns 36, 37 are thus preferably always temporarily. Thisrenders possible freeing up area in the grid, dependent on the operationof the container handling vehicles 9 and or other vehicles moving on therail system 8.

The multi trolley vehicle(s) 100 is arranged to travel rectilinearly onor above the rail system 8 along at least one row 40 of said gridcolumns. Each drive vehicle 70, 71 can occupy a single cell or more thanone cell in the direction perpendicular to the driving direction.Similarly, each trolley 72′ can occupy a single cell or more than onecell in the direction perpendicular to the driving direction. The drivevehicle(s) 70, 71 can occupy more or less rows than the trolleys 72′.

As is disclosed in FIG. 5B, the trolleys 72′ are shown as having equalextension in the travel direction of the multi trolley vehicle 100 asone single cell, i.e. the area occupied by one trolley 72′ is notextending outside a single cell. In this setup, neighboring trolleys 72′may pick up storage containers 6 from neighboring storage columns 5.

FIG. 6A is a perspective view of an embodiment of the invention where amulti trolley vehicle 100 having a first and second drive vehicle 70, 71connected at each end to a trolley assembly 72 moves on a double rail 79above the rail system 8 where container handling vehicles 9 operates.

FIG. 6B is a side view of the embodiment in FIG. 6A.

FIGS. 7A and 7B are examples of an embodiment of the invention wherestorage containers 6 are lowered down onto the trolleys 72′ in thetrolley assembly 72 by container handling vehicles 9 or another, i.e. anupper multi trolley vehicle 100 (FIG. 7B), which container handlingvehicles 9 and multi trolley vehicle 100 operate on a rail system 8located above a double rail 79 where the multi trolley vehicle 100operates. FIG. 7A is a perspective view, while the two figures on FIG.7B are, respectively, in the direction of travel of the multi trolleyvehicle 100 (to the left), and a side view of FIG. 7A (to the right). Asis disclosed in FIGS. 7A and 7B, each trolley 72′ in the lower trolleyassembly 72 may either comprise open-top boxes (see details in FIG. 7A,the three boxes closest to the second drive vehicle 71) which canreceive storage containers 6 from above or, alternatively, the trolleys72′ in the trolley assembly 72 can have a receiving surface in the formof a platform or bed possibly provided with connecting elements and/orfriction elements for receiving the storage containers 6 (see details inFIG. 7A, the three trolleys 72′ closest to the first drive vehicle 70).

Instead of transporting storage containers 6 away from the rail system,the multi trolley vehicle 100 may transport storage containers 6 to therail system, where storage handling vehicles 9, or other devices withlifting devices, can retrieve the storage containers 6 from the trolleyassembly 72 and place them in dedicated storage columns 5 in the grid 4.

As an alternative to receiving storage containers from the depictedstorage handling vehicles 9 in FIG. 7A, other vehicles operating on therail system 8, such as another multi trolley vehicle 100 (FIG. 7B) or aport access vehicle (see for example FIG. 12), may lower or retrieve thestorage containers 6 to and from the trolleys 72′.

In the embodiment of FIGS. 7A and 7B, it is clear that the multi trolleyvehicle 100 can function as a conveyor belt, for example in the portzone, rendering the use of traditional conveyor belts in this areasuperfluous. This is rendered possible by for example allowing thetrolley assembly 72 to cooperate with one or more lifting arrangements,for example the container handling vehicles 9 or another multi trolleyvehicle 100 where the trolleys comprise lifting devices, the port accessvehicle 45, any vehicle located in a horizontal plane above wheredisclosed lower multi trolley vehicle 100 operates. If another multitrolley vehicle 100 is used, this multi trolley vehicle 100 (i.e. thedisclosed upper multi trolley vehicle 100 in FIG. 7B) preferablyoperates in the same X and Y rows but in different Z locations as thedisclosed lower multi trolley vehicle 100. e.g. operating in the sameplane as the disclosed container handling vehicles and the upper multitrolley vehicle 100 operate (as disclosed in FIG. 7B). With reference toFIGS. 8A and 8B, the multi trolley vehicle 100 may occupy one row, ormay extend over more than one row 40, e.g. 1, 2, 3, 4, 5 . . . 10 rowsto increase the transport capacity. Thus, the size of the at least onetrolley 72′ may occupy a single cell or one trolley 72′ may occupy morethan one cell both in the direction of travel and/or in the directionperpendicular to the direction of travel (i.e. in the X and/or Ydirections on the rail system 8). In the latter case, each trolley 72′can be provided with a plurality of lifting devices, e.g. elevators (forexample as disclosed in FIGS. 2B and 2C or elevators connected to a topend of the trolley 72′ for lifting and lowering storage containers 6between a column in the grid or rail system 8 and volume compartment forfully containing a storage container in the trolley 72′), for liftingand lowering storage containers 6 between a column 5 in the grid 4 andthe trolley 72′, which number of lifting devices correspond to thenumber of cells occupied by the trolley 72′.

The double rail 79 is disclosed supported on dedicated support legs 49,but may also be suspended from the ceiling, be fastened to the walls, bemounted on the grid structure etc.

In general, transporting the storage containers 6 between the transfercolumns 36, 37 or any other storage column 5 and the deployment area ina substantially horizontal plane, for example on a double rail 79, whichis located above or below the container handling vehicles 9, i.e. aboveor below the plane where the container handling vehicles 9 travel acrossthe grid 4, any interference on the transfer of the storage containers 6between the transfer columns 36, 37 and the deployment area may have onthe movement of the container handling vehicles 9 will be minimized.

Not including the port zones 26, the grid 4 in the example of FIG. 11 is36 cells wide in the X direction and 50 cells long in the Y direction.In the Z direction (cf. FIG. 12), the grid 4 may have a height of fivecells. It is understood, however, that the grid 4, in principle, can beof any size. In particular, it is understood that grid 4 can beconsiderably wider and/or longer than disclosed in FIGS. 5 and 6. Forexample, the grid may have a horizontal extent of more than 600×600 gridcells. Also, the grid 4 can be considerably deeper than disclosed inFIG. 12. For example, a grid may be more than 10 grid cells deep (in theZ direction). In the embodiment of FIG. 11, multi trolley vehicles 100with drive vehicles 70, 71 and trolley assemblies 72 can travel alongany one or more of rows 38, 39, 40 in the transfer zone 35, and thetransfer zone 35 can be e.g. any one of rows 38, 39 and or 40 (oralternatively additional rows). In the specific embodiment of FIG. 11,the transfer zone 35 to the left in the Figure, i.e. denoted G1,discloses a multi trolley vehicle 100 which is three cells wide(X-direction) and seven cells long (Y-direction). Thus, the multitrolley vehicle 100 serves all three rows 38, 39, 40 in transfer zone35. In transfer zone 35 to the right in the Figure, i.e. denoted G2,there are three multi trolley vehicles 100 serving the transfer zone 35,with one multi trolley vehicle 100 in each of the rows 38, 39, 40,including: in row 38 a multi trolley vehicle 100 which is one cell wideand nine cells long, in row 40 a multi trolley vehicle 100 which is onecell wide and 6 cells long, and in row 39 a multi trolley vehicle 100which is one cell wide and 4 cells long. It is also possible that themulti trolley vehicle 100 could be one cell long and 2 or more cellswide.

Alternatively, the multi trolley vehicles 100 with at least one drivevehicle 70, 71 and trolley assembly 72 can travel along rows 38 and 39,while a port access vehicle 45 (features of the port access vehicle 45explained in greater detail below) can be arranged to travel, or befixed at particular columns, along row 40 for cooperation with the multitrolley vehicles 100.

Each transfer zone 35 comprises transfer columns 36, 37 arranged totemporarily hold storage containers 6 when in transit between thestorage zone 25 and the port zones 26. The transfer columns includedrop-off columns 36 where the container handling vehicles 9 can drop offstorage containers retrieved from the grid 4, and pick-up columns 37where the container handling vehicles 9 can pick up storage containers 6to be stored in the grid 4.

The drop-off columns 36 are arranged in a row 38 extending in the Ydirection from the exit ports 28. The pick-up transfer columns 37 arearranged in a row 39 extending in the Y direction from the entry ports29. An intermediate column row of grid columns 40 is positioned betweenrows 38 and 39. In other words, the drop-off columns 36 and the pick-upcolumns 37 are separated by the intermediate column row 40.

In the disclosed embodiment, the drop-off columns 36 and the pick-upcolumns 37 occupy positions Y=1 to Y=43 in each row 38 and 39.Consequently, the drop-off columns 36 and the pick-up columns 37 are 43grid cells long, i.e. they extend 43 grid cells into the transfer zone35. Since the number of drop-off and pick-up columns 36, 37 is largerthan the number of ports 28, 29, the likelihood of a container handlingvehicle 9 not finding a vacant drop-off column 36 where it can deliver astorage container is low.

FIG. 11 also discloses an example of a port zone 26 in more detail. Eachport zone 26 comprises seven exit ports or exit port columns 28 throughwhich the storage containers 6 can be brought out of the grid 4 to beaccessed from outside of the grid 4. Each port zone 26 also comprisesentry ports or entry port columns 29 through which storage containers 6can be brought into the grid 4 to be stored in the storage columns 5. Anaccess and transfer system 31 is arranged for transporting storagecontainers between the ports 28, 29 and an access station 32, which inthe disclosed embodiment is a picking and stocking station. The accessand transfer system 31 comprises a first conveyor 33 which is arrangedunderneath the exit ports 28 to transport storage containers from theexit ports 28 to the access station 32, and a second conveyor 34 whichis arranged underneath the entry ports 29 to transport storagecontainers from the access station 32 to the entry ports 29. The railsystem 8 extends into the port zones 26 of the grid 4.

Port access vehicles are operated above the grid 4 for transferringstorage containers 6 between the transfer zones 35 and the port zones26. As will be discussed in more detail in the following, each portaccess vehicle 45 is arranged to transfer storage containers 6 above theoperating plane of the container handling vehicles 9, i.e. in a planeabove the operating space of the container handling vehicles 9 and anymulti trolley vehicles 100, thus allowing the port access vehicle 45 totransfer a storage container 6 over a drop-off or pick-up transfercolumn 36, 37 even if a container handling vehicle 9 or multi trolleyvehicle 100 occupies the grid location above that drop-off or pick-uptransfer column 36, 37. Consequently, multi trolley vehicles 100 andcontainer handling vehicles 9 can be dropping off or picking up storagecontainers from drop-off or pick-up transfer columns 36, 37 while theport access vehicle 45 simultaneously transfers other storage containers6 between the transfer zone 35 and the port zone 26 above the containerhandling vehicles 9.

A port access vehicle 45 which can form part of the system will now bediscussed in more detail with reference to FIGS. 4, 11-14.

The port access vehicle 45 may operate along the grid columns in row 40(cf. FIG. 11), i.e. along a row of grid columns which extend into thegrid from the port zone 26. The port access vehicle 45 may comprise aplurality of vehicle sections 46 which are connected in a train-likeconfiguration, i.e. one after the other (e.g. cf. FIG. 12). Each vehiclesection 46 comprises a vehicle body 47 which has a footprint whichgenerally corresponds to the lateral extension of a grid column 12, thusallowing the port access vehicle to pass between container handlingvehicles 9 or multi trolley vehicles 100 which are dropping off orpicking up storage containers in the transfer zone. At the lower end ofthe vehicle body 47, a set of wheels 48 is mounted and configured toallow the vehicle section 46 to travel on the rail system 8 in the Ydirection along row 40.

In the train of vehicle sections 46 making up the port access vehicle45, the set of wheels 48 of at least one the vehicle sections 46 ismotorized in order to propel the port access vehicle 45.

The vehicle section 46 comprises a horizontal bar or frame 50 which ismounted to the top of the vehicle body 47 and extends horizontally fromboth sides of the vehicle body 47 orthogonal to the dedicated directionof travel of the vehicle section 46, which dedicated direction of travelis defined by the set of wheels 48. In other words, when in operation onthe rail system 8 or e.g. on a monorail above the rail system 8, thehorizontal bar 50 extends in the X direction (e.g. cf. FIG. 4). On bothsides of the vehicle body 47, the horizontal bar 50 supports a containerlifting and holding device 53, 54. Each lifting and holding device 53,54 comprises a container gripping device 51, 52, which can be loweredfrom the horizontal bar 50 to grip and hold a storage container 6. Thegripping devices 51, 52 can be individually lowered in order to pick upand drop off storage containers independently of each other.

The lifting and holding devices 53, 54 are arranged to hold storagecontainers in a raised, holding position when the port access vehicle 45transports the storage containers 6 between the transfer zone 35 and theport zone 26. The vehicle body 47 of the vehicle sections 46 has avertical extension which is sufficient to allow the lifting and holdingdevices 53, 54 to hold the storage containers 6 in a holding positionwhich is above the operating space of the container handling vehicles(e.g. cf. FIG. 4).

With reference to FIGS. 9A-9B, instead of equipping the trolleys 72′with lifting devices or elevators, each trolley 72′ may comprise aclosed bottom end and an open top end (see FIGS. 7A, 7B, 9B) forreceiving storage containers 6 from above. This is rendered possible byfor example allowing the trolley assembly 72 to cooperate with one ormore lifting arrangements, for example the port access vehicle 45, orusing another multi trolley vehicle 100 located in the same X and Y rowsbut in different Z locations, i.e. arranged directly below or above. Itis advantageous if the lifting arrangement comprises a first liftingdevice arranged to carry a storage container 6 from one of the transfercolumns 36, 37 and position it in or on the at least one trolley 72′ fortransport to the deployment area, and a second lifting arrangement, e.g.another or the same port access vehicle 45 or a stationary liftingarrangement, arranged at the deployment area for picking up the storagecontainer 6 from the trolley 72′. Similarly, the system can be adaptedto transport the storage container 6 from the deployment area to any onetransfer columns 36, 37 in the transfer zone 35. The multi trolleyvehicle 100 can be used for transporting the storage containers 6 to adeployment area, for example a port 26, where the same or alternativelyanother port access vehicle 45 can lift the storage containers 6 fromthe trolleys 72′ and place them in respective columns or ports etc. Theport access vehicle 45 is then either moved along row 40 or isstationary arranged in the deployment area or a factory area orproduction facility 80 (see FIG. 16C), e.g. the port zone 26. When themulti trolley vehicle 100 arrives in the port zone 26, the port accessvehicle 45 lifts the storage containers 6 from above and lowers thestorage container into a grid column which is directly into an exit portcolumn 28 or adjacent an exit port column 28. The target storagecontainer is then lowered into exit port column 28 and positioned onconveyor 33 (see FIG. 12), which transports the target storage container6 to the access station 32. Instead of a conveyor, it is possible, asdiscussed above, to use at least one multi trolley vehicle 100 totransport the storage containers 6 to the access station 32.Furthermore, using a multi trolley vehicle 100 instead of e.g. aconveyor belt results in a significantly longer possible operatingdistance between the exit port column 28 in the grid and the accessstation 32 (i.e. the access station 32 does not have to be close to theexit port column 28 as the multi trolley vehicle render possible fasterand longer possible transport distance between the exit port column 28and the access station 32 than is possible by using a conveyor belt) aswell as a possibly faster transfer of storage containers.

With reference to FIG. 12, once accessed at the access station 32, thetarget storage container is transferred back into the grid 4 to onceagain be stored in a storage column 5 in the storage zone 25. Thisoperation is essentially the reversal of the above-discussed operationof fetching a storage container from the grid and involves:

-   -   transporting the target storage container from the access        station 32 to one of the entry port columns 29 using conveyor 34        or a multi trolley vehicle 100 (e.g. by arranging the storage        containers horizontally below the different trolleys 72′ and        using the lifting device(s) in each trolley 72′ to lift the        storage container 6, or, if the trolley 72′ has a closed bottom        end an operator can place the storage container(s) directly onto        the trolley 72′);    -   positioning the port access vehicle 45 or a multi trolley        vehicle 100 in the port zone 26 with the vehicle body 47 of one        of the vehicle sections 46 located above a grid column adjacent        entry port column 29 or the trolleys 72′ located above an entry        port column;    -   lowering the gripping device 52 of the vehicle section 46 or the        lifting device of the trolley(s) 72′ into the entry port        column(s) 29, engaging the target storage container(s) and        lifting it/them to the transfer position;    -   either dropping the storage containers onto trolleys 72′ in a        trolley assembly 72 using the port access vehicle 45 before        transporting the storage containers with the multi trolley        vehicle 100 along row 40 from the port zone 26 to the transfer        zone 35, where the port access vehicle 45 is positioned so that        the vehicle body 47 of the vehicle section 46 holding the target        storage container becomes located above a grid column adjacent a        pick-up transfer column 37 or, if the trolleys 72′ are provided        with lifting devices, transporting the storage containers 6 with        multi trolley vehicle 100 directly along rows 38, 39 or 40 from        the port zone 26 to the transfer zone 35 with the trolleys 72′        directly above pick-up transfer column(s);    -   lowering the target storage container(s) 9 into the pick-up        transfer column(s) 37;    -   instructing a container handling vehicle 9 to move to the        pick-up column 37 and retrieve the target storage container(s);        and    -   moving the container handling vehicle 9 to the storage column(s)        where the target storage container(s) is/are to be stored and        positioning the target storage container(s) in its intended        position in the stack.

The port access vehicle 45 may be operated on the grid, e.g. be arrangedto travel along the rail system 8 of the grid. However, as disclosed inFIGS. 9A and 9B and 10, the port access vehicle 45 may be operated on amonorail 89 (or other form of overhead rail system) arranged in ahorizontal plane above the rail system 8 and the multi trolley vehicle100 can be operated on the rail system 8.

When the container handling vehicle 9 has positioned the target storagecontainer in the drop-off transfer column 36 and left the transfer zone35, e.g. to retrieve another storage container 9 from the grid 4, themulti trolley vehicle 100 is moved along its dedicated row, i.e. row 38,39 or 40 and positioned with one of its trolleys 72′ located above thegrid column which is at the same drop-off transfer column 36 in whichthe container handling vehicle 9 has positioned the target storagecontainer. One of the trolleys 72′ then retrieves the target storagecontainer 6 from the drop-off transfer column 36 by lowering the liftingdevice, gripping the target storage container and raising it into thecompartment in the trolley. Similarly, if the footprint of the trolleys72′ occupy maximum one cell the other trolleys 72′ can pick up storagecontainers from neighboring columns in the same row(s) in the transferzone 35. The multi trolley vehicle 100 is then moved to e.g. port zone26 where the trolleys 72′ lower the storage containers 6 into exit portcolumn(s) 28 and positions the storage container(s) 6 on for example aconveyor 33 or a multi trolley vehicle 100, which transports the targetstorage container(s) to the access station 32.

In the transfer zones 35, the storage containers 9 are advantageouslystored in the uppermost layer of the grid, i.e. in the layer identifiedas Z=1. This will minimize the distance the gripping devices of thecontainer handling vehicles 9, the trolleys 72′ in the multi trolleyvehicle 100 and port access vehicle 45 needs travel when dropping offand picking up storage containers 6 in the transfer zone 35, which willallow for rapid turnaround of the storage containers temporarily storedtherein.

In order to allow the storage containers to be temporarily stored in theuppermost layer in the respective transfer columns, each transfer columnmay comprise stopping devices (not shown), e.g. clamps attached to theupright members 2 surrounding each transfer column, which clamps preventthe storage container from being lowered into the transfer column beyondlevel Z=1. Of course, the clamps can be attached to the upright membersdeeper down the transfer column, thus allowing the storage containers tobe temporarily stored at deeper levels than Z=1. Alternatively, thistemporary storage can be achieved by stacking a plurality of emptystorage containers up to the location Z=1 in all of the storage columns5 defined by the transfer zone 35.

The storage containers can be temporarily stored at different levels indifferent transfer columns. Also, in some applications it may beadvantageous to simultaneously store more than one storage container ina transfer column. However, in such an application the trolley 72′ needsto be configured to carry out a digging operation in order to retrieve astorage container temporarily stored below another temporarily storedstorage container.

Due to the modular character of the multi trolley vehicle 100, the multitrolley vehicle 100 can be easily adapted to different transfer zonesizes and/or deployment area configurations by adding or removingtrolleys 72′. Consequently, the multi trolley vehicle 100 can beconfigured to simultaneously transfer a plurality of storage containersbetween the transfer zone 35 and the deployment area. For example, whentraveling from the transfer zone 35 to the port zone 26, each trolley72′ can be employed to carry a storage container. Likewise, whentraveling from the port zone 26 to the transfer zone 35, each trolley72′ can be employed to carry a storage container.

FIG. 15 is a top view of a grid 4 of an automated storage and retrievalsystem according to the invention where possible positions and shapes oftransfer zones 35 and port zones 26 are indicated. Areas shaded darkgrey indicate transfer zones 35 and areas shaded light grey indicateport zones 26. Each port zone comprises ports 28, 29 and each transferzone 35 comprises transfer columns arranged in rows. In the disclosedexample each transfer zone 35 is associated with at least one port zone26. White grid cells indicate storage columns 5 defining the grid'sstorage zone 25. Automated container handling vehicles 9 are operated onthe grid 4 or rail system 8 as previously discussed, i.e. to transportstorage containers 6 between the storage columns 5 and the transferzones 35 and are shown as black grid cells. Double arrows extendingalong the port and transfer zones indicate the operation of port accessvehicle operating as previously discussed, i.e. to transport the storagecontainers between the transfer zones 35 and the port zones 26. Darkgrey grid cells indicate multi trolley vehicles 100 operating on thegrid between the transfer zone 35 and the port zone 26.

The region labelled A shows a transfer zone 35 with a non-rectangularshape. Since the length of the transfer zone 35 in the Y directionexceeds three rows, the port access vehicle 45 serving the transfer zone35 should be configured with bars or frames extending or beingextendable in the Y direction in order to access the outermost drop-offand pick-up transfer columns. The bars may for example be telescopicallyextendible bars. The region labelled B shows a squared-shaped transferzone 35 which may be accessed by two port access vehicles, one operatingin the X direction and one in the Y direction. The region labelled Cshows a configuration where the port zone 26 does not form an extendingportion of the grid 4. The region labelled D shows a transfer zone 35which is located adjacent the grid circumference.

FIGS. 16A, 16B and 16C show examples of different deployment areas. FIG.16A shows a deployment area being another grid system 4 (for exampleanother storage system or warehouse) with a double rail 79 between thegrid or rail systems 4, 8. Another double rail (not shown in the Figure)can be arranged at another level than the disclosed double rail 79. Oneor more multi trolley vehicles 100 (indicated in shaded grey on theFigure) can operate on the double rail 79. FIG. 16B shows the deploymentareas being two other storage/warehouse systems with dedicated gridsystems 4 and with a double rail between the different grid systems 4 inthe different storage systems. FIG. 16C shows the deployment area beinga factory area or production facility 80 where the multi trolleyvehicles 100 are configured to drive on a double rail formed as a loopbetween the grid or rail system 4, 8 and the factory area or productionfacility 80. The arrow A in FIG. 16C indicates the direction of travelalong the loop 81 for the multi trolley vehicles 100. If it is a singledouble rail between the grid system 4 and the factory area or productionfacility 80, it is advantageous that the different multi trolleyvehicles 100 travel in the same direction to avoid collision etc.However, if there are multiple rails either on the same level or atdifferent levels the different multi trolley vehicles 100 can travel inboth directions on the rail(s). It shall be noted that the relativelarge size of the multi trolley vehicles 100 compared to the rails inFIGS. 16A-16C are for illustrative purposes only and it is clear thatthe multi trolley vehicle 100 can be of less width (e.g. the same widthas the rail).

In the preceding description, various aspects of an automated storageand retrieval system according to the invention have been described withreference to the illustrative embodiment. However, this description isnot intended to be construed in a limiting sense. Various modificationsand variations of the illustrative embodiment, as well as otherembodiments of the system, which are apparent to persons skilled in theart, are deemed to lie within the scope of the present invention asdefined by the following claims.

List of references  1 Framework structure  2 Upright member  3Horizontal member  4 Storage grid  5 Storage column  6 Storage container 7 Stack  8 Rail system  9 Container handling vehicle 10 First set ofrails 11 Second set of rails 12 Grid column 13 Vehicle body 14 First setof wheels 15 Second set of wheels 16 Lifting device (elevator) 17Connection 18 Lifting frame 19 First port column 20 Second port column21 22 Footprint 23 24 25 Storage zone 26 Port zone 27 28 Exit port/exitport column 29 Entry port/entry port column 30 31 Access and transfersystem 32 Access station 33 First conveyor 34 Second conveyor 35Transfer zone 36 Drop-off column 37 Pick-up column 38 Row 39 Row 40Intermediate column row 41 45 Port access vehicle 46 Vehicle section 47Vehicle body 48 Set of wheels 49 Support leg 50 Horizontal bar or frame51 Container gripping device 52 Container gripping device 53 Lifting andholding device 54 Lifting and holding device 61 Rail structure 70 Firstdrive vehicle 71 Second drive vehicle 72 Trolley assembly  72′ Trolley79 double rail 80 Factory area or production facility 81 Loop 89Monorail 100  Multi trolley vehicle A Arrow, direction of travel

The invention claimed is:
 1. An automated storage and retrieval systemcomprising: a rail system comprising a first set of parallel tracksarranged in a horizontal plane and extending in a first direction, and asecond set of parallel tracks arranged in the horizontal plane andextending in a second direction that is orthogonal to the firstdirection, wherein the first and second sets of tracks form a gridpattern in the horizontal plane comprising a plurality of adjacent gridcells, each grid cell comprising a grid opening defined by a pair ofneighboring tracks of the first set of tracks and a pair of neighboringtracks of the second set of tracks; and a plurality of stacks of storagecontainers arranged in storage columns located beneath the rail system,wherein each storage column is located vertically below a grid opening;wherein the automated storage and retrieval system further comprises: amulti trolley vehicle for transporting storage containers between thestorage columns and at least one deployment area, the multi trolleyvehicle being movable on any rail including: on the rail system or in ahorizontal plane above or below the rail system, on dedicated transportrails between the rail system and deployment area, on a double railabove or below the rail system or combinations thereof; the deploymentarea provides direct access to an area outside the grid pattern formedby the first and second sets of tracks, the multi trolley vehiclecomprising: a trolley assembly comprising a plurality of trolleyscoupled to each other along at least one of the first direction and thesecond direction, wherein each trolley provides at least one containervolume for storing at least one of the storage containers and whereineach trolley comprises moving devices allowing movement of the trolleyassembly in at least one of the first direction and the seconddirection, and wherein at least one of the trolleys comprisesnon-motorized moving devices, and a first drive vehicle coupled to thetrolley assembly, the first drive vehicle comprising motorized movingdevices allowing self-propelled movement of the first drive vehicle andthereby the multi trolley vehicle in at least one of the first andsecond directions corresponding to the at least one of the first andsecond directions of the trolley assembly, such that the multi trolleyvehicle is horizontally movable.
 2. The automated storage and retrievalsystem according to claim 1, wherein all moving devices in each trolleyare non-motorized.
 3. The automated storage and retrieval systemaccording to claim 1, wherein the moving devices comprise wheels.
 4. Theautomated storage and retrieval system according to claim 1, wherein adrive system in the at least first drive vehicle comprises a hub motorarranged within each of the moving devices.
 5. The automated storage andretrieval system according to claim 1, wherein the system furthercomprises: a port access vehicle that comprises a plurality of vehiclesections that are connected one after the other in a train-likeconfiguration, each vehicle section being configured to carry at leastone storage container, and a plurality of container lifting and holdingdevices enabling simultaneous transport of a plurality of storagecontainers between the rail system and the deployment area, wherein theport access vehicle is arranged to transport the storage containersbetween the rail system and the at least one deployment area in a planelocated above the rail system.
 6. The automated storage and retrievalsystem according to claim 1, further comprising a plurality of containerhandling vehicles that are operated on the rail system for retrievingstorage containers from and storing storage containers in the storagecolumns, and for transporting the storage containers horizontally acrossthe rail system, and wherein the rail system comprises at least onetransfer zone with underlying transfer columns for temporarily storingstorage containers when in transit between the plurality of storagecolumns and the at least one deployment area, wherein the containerhandling vehicles are arranged to transport the storage containersbetween the storage columns and the at least one transfer zone.
 7. Theautomated storage and retrieval system according to claim 1, furthercomprising a second drive vehicle with motorized driving devicesallowing self-propelled movement of the second drive vehicle in at leastone of the first direction and the second direction, wherein seconddrive vehicle is connectable to a second end of the trolley assembly. 8.The automated storage and retrieval system according to claim 7, whereinthe motorized moving devices of the first drive vehicle connected to thefirst end of the trolley assembly are configured to allowself-propelled, one-way movement along at least one of the firstdirection and the second direction and the motorized moving devices ofthe second drive vehicle connected to the second end of the trolleyassembly are configured to allow self-propelled, one-way movement alongan opposite direction of the at least one first direction and the seconddirection.
 9. The automated storage and retrieval system according toclaim 1, further comprising: a mechanical connection comprising at leastone bracket fixed to adjacent trolleys or drive vehicle(s) between eachtrolley in the trolley assembly and the at least first drive vehicle isconfigured to allow movements along the direction of couplingcorresponding to at least 1% of a length of the respective coupling,thereby allowing the multi trolley vehicle to follow curves in a trackor go up a slope.
 10. The automated storage and retrieval systemaccording to claim 9, wherein the mechanical connection isdisconnectable.
 11. The automated storage and retrieval system accordingto claim 1, wherein each trolley comprises a closed bottom end and anopen top end for receiving storage containers from a vehicle comprisinga lifting device and moves on or above the rail system.
 12. Theautomated storage and retrieval system according to claim 11, whereinthe deployment area is a port or port area, wherein the port or portarea is arranged within or outside of the grid pattern, either extendingalong an end row or extending into or out from the grid pattern.
 13. Theautomated storage and retrieval system according to claim 12, whereinthe multi trolley vehicle moves in a plane horizontally below the railsystem.
 14. A multi trolley vehicle for operation on an automatedstorage and retrieval system comprising: a trolley assembly comprising aplurality of trolleys coupled to each other along at least one of afirst direction and a second direction, and a first drive vehiclecoupled to the trolley assembly, wherein the automated storage andretrieval system comprises: a rail system comprising a first set ofparallel tracks arranged in a horizontal plane and extending in a firstdirection, and a second set of parallel tracks arranged in thehorizontal plane and extending in a second direction that is orthogonalto the first direction, wherein the first and second sets of tracks forma grid pattern in the horizontal plane comprising a plurality ofadjacent grid cells, each grid cell comprising a grid opening defined bya pair of neighboring tracks of the first set of tracks and a pair ofneighboring tracks of the second set of tracks; and a plurality ofstacks of storage containers arranged in storage columns located beneaththe rail system, wherein each storage column is located vertically belowa grid opening; wherein the multi trolley vehicle is for moving storagecontainers between the storage columns and at least one deployment area,the deployment area provides direct access to an area outside the gridpattern formed by the first and second sets of tracks; wherein the multitrolley vehicle is movable on any rail including: on the rail system orin a horizontal plane above or below the rail system, on dedicatedtransport rails between the rail system and the deployment area, on adouble rail above or below the rail system or combinations thereof;wherein each trolley provides at least one container volume for storingat least one of the storage containers, wherein each trolley comprisesmoving devices allowing movement of the trolley assembly in at least oneof the first direction and the second direction, and wherein at leastone of the trolleys comprises non-motorized moving devices, and thefirst drive vehicle comprising motorized moving devices allowingself-propelled movement of the first drive vehicle and thereby the multitrolley vehicle in at least one of the first and second directionscorresponding to the at least one of the first and second directions ofthe trolley assembly, wherein the multi trolley vehicle is horizontallymovable.
 15. A method of operating an automated storage and retrievalsystem, the automated storage and retrieval system comprising: a railsystem comprising a first set of parallel tracks arranged in ahorizontal plane and extending in a first direction, and a second set ofparallel tracks arranged in the horizontal plane and extending in asecond direction that is orthogonal to the first direction, wherein thefirst and second sets of tracks form a grid pattern in the horizontalplane comprising a plurality of adjacent grid cells, each grid cellcomprising a grid opening defined by a pair of neighboring tracks of thefirst set of tracks and a pair of neighboring tracks of the second setof tracks; and a plurality of stacks of storage containers arranged instorage columns located beneath the rail system, wherein each storagecolumn is located vertically below a grid opening; wherein the methodcomprises: connecting a trolley assembly comprising a plurality oftrolleys to at least a first drive vehicle comprising motorized movingdevices to form a multi trolley vehicle, and utilizing said multitrolley vehicle to transport the storage containers between the storagecolumns and at least one deployment area, the multi trolley vehiclebeing movable on any rail including: on the rail system or in a planehorizontally above or below the rail system, on dedicated transportrails between the rail system and deployment area, on a double railabove or below the rail system or combinations thereof, wherein thedeployment area provides direct access to an area outside the gridpattern formed by the first and second sets of tracks.
 16. The methodaccording to claim 15, further comprising: operating a control system todefine at least one transfer zone comprising a plurality of transfercolumns for temporarily storing storage containers when in transitbetween the storage columns and the at least one deployment area;utilizing container handling vehicles that are operated on the railsystem for retrieving storage containers from and storing storagecontainers in the transfer columns, and for transporting the storagecontainers horizontally across the rail system; and wherein transportingthe storage containers between the transfer columns and the at least onedeployment area comprises utilizing a port access vehicle cooperatingwith the multi trolley vehicle, wherein the port access vehiclecomprises a plurality of vehicle sections that are connected one afterthe other in a train-like configuration in a horizontal plane that islocated above the horizontal plane of the rail system where thecontainer handling vehicles and the multi trolley vehicle operate,wherein each vehicle section is configured to carry at least one storagecontainer, and wherein the trolleys comprise a closed bottom end areadapted to receive storage containers from above, and wherein the methodcomprises operating the port access vehicle to lower storage containerson to the trolleys, and subsequently operating the multi trolley vehicleto transport the storage containers to the deployment area, wherein asecond port access vehicle is arranged in the deployment area forlifting the storage containers from the trolleys.